558 



Ooldea, or indeed in South Australia, but we have placed 

 in this class the many parasites, chiefly Loranthus, spp., which 

 are found in the Ooldea florula. 



Tlie classification of a flora into these life-forms may be 

 utilized in the following way, as illustrated by the table below 

 (Table III.). For any locality the total number of species 

 analysed is given, followed by the results given as percent- 

 ages according to the grouping above. ''Such an analysis for 

 any region is termed the biological or phy to-climatic spectrum. 

 The normal spectrum is the base line, and the outstanding 

 features of the other spectra are deduced by comparison, not 

 by the highest percentage in their own curve, but by the 

 amount of variation from the normal spectrum. Tlie latter is 

 ideally the phyto-climatic spectrum of the whole earth; 

 actually it is obtained by computation, and at present is given 

 only as approximate. It was arrived at by first selecting 

 1,000 representative species and then taking 400 of these, 

 which were carefully analysed. This number^ 400, has been 

 carefully controlled in various ways," ^i^) which, however, need 

 not be considered here. 



Table III. 



Biological spectrum of Ooldea district compared with that of 

 other arid regions : — 



Percentage of Species belonging to each Life-form 

 Total ^ — — -^ 



Species MM M N Ch H 6 HH TH E S 



Normal Spectrum 400 6 17 20 9 27 3 1 13 3 1 



Ooldea ... ... 188 -5 19 23 14 4 -5 — 35 4» — 



Libyan Desert ... 194 — 3 9 21 20 4 1 42 — — 



Aden 176 — 7 26 27 19 3 — 17 — 1 



Madeira Lowlands 213 — 1 14 7 24 — 3 61 — — 



Transcaspian ... 768 10 7 27 9 o 41 — — 



Death Valley ... 294 — 2 21 7 18 2 5 42 — 3 



• These epiphytes are all parasites, not true epiphytes, see text. 



Considering the spectrum of the Ooldea region in relation 

 to the normal, the absence of tall trees, (i6) (MM*) is as 

 marked a feature as is the smaller number of perennial 

 herbaceous plants, i.e., hemicryptophytes and geophytee. On 

 the other hand, the micro and nanophanerophytes, and also 

 the chamaephytes, are all in excess of the normal percentage. 

 The departure from the normal is most marked in the chamae- 

 phytes (5 per cent, increase), but the two Phanaerophyte 



(15) Smith, W. G., loc. cit., p. 18. ~~ 



{16) Casuarina lepidophloia, as found growing at the "Oak 

 forest," was the only tree over 8 metres. 



